While there has been considerable progress, more work remains because a woman dies of pregnancy-related complications every two minutes, according to the report.

The report from the World Health Organization, United Nations Children's Fund, United Nations Population Fund and the World Bank said about 99 percent of maternal deaths occur in developing nations, and most are preventable. Deaths among women giving birth were 15 times higher than in developed countries, said the report, titled "Trends In Maternal Mortality: 1990 - 2010."

It said there were an estimated 287,000 maternal deaths in 2010, a decline of 47 percent since 1990.

Sub-Saharan Africa accounted for 56 percent of the deaths and southern Asia another 29 percent, totaling 85 percent of the global tally of maternal deaths in 2010. Reduced rates in Asia are supposedly attributed to China's one child policy. Two countries accounted for a third of global maternal deaths: India at 19 percent and Nigeria at 14 percent, the report said.

The United States had 21 maternal deaths per 100,000 live births, a total of 880 maternal deaths in 2010, the report said. U.S. maternal deaths rose an average of 2.5 percent a year from 1990 to 2010, it said.

The U.S. did not rank in the top tier of countries in terms of maternal health, falling behind Western Europe, Canada and Australia, and ranking on a par with Russia, Central and South America and parts of North Africa, it found.

The report defined maternal death as occurring during pregnancy or within 42 days of termination of pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes.

According to the New York Times, the new figures were in response to research from the Institute for Health Metrics and Evaluation -- founded by the Bill and Melinda Gates Foundation - which said the previous WHO/UN figures were inaccurately high. Their results, published in April 2010 in The Lancet, said that only 343,000 maternal deaths took place in 2008 as opposed to the over 500,000 that the WHO/UN previously said. The UN revised the numbers five months later.